Electric stringed instruments have long been known in the music field. By far the most commonly known and used of these instruments is the electric guitar, which has been around since the 1930's.
The signal from an electric guitar originates as mechanical vibrations caused by the musician playing the strings of the instrument. In a conventional electric guitar, these mechanical vibrations are picked up by an electro-mechanical transducer, known as a “pickup,” located on the body of the guitar near the strings. The traditional pickup has several magnetic poles, each of which is positioned in close proximity to a respective string of the guitar. The poles are encircled by a conductive wire coil or coils, such that when the strings vibrate, the magnetic field of the poles is disturbed and an electrical signal is generated through the coil(s). In this way, the pickup converts an input in the form of mechanical vibrations into an output in the form of an electrical signal; hence the description of the pickup as “electro-mechanical.”
The electrical signal created by the pickup may then be processed to create desired musical attributes called “effects,” e.g., pitch, volume, or tone. This processing is typically done by a variety of equipment, such as amplifiers, foot pedals, or other equipment designed for creating such effects. After any desired effects have been produced, the signal is ultimately sent through speakers where it is converted into musical sounds. Traditional pickups are thus passive devices whose sole purpose is to convert mechanical energy into electrical energy, with any changes to the electrical signal created by the pickup being made extraneously to the pickup.
Traditional pickups may be divided into two broad categories: (1) single-coil pickups; and (2) divided pickups. Both types of pickups have several magnetic poles, with each pole being paired in close proximity to a respective string of the instrument. However, single-coil pickups have only one wire coil, which encircles all of the pickup's magnetic poles as a group. Therefore, single-coil pickups produce only one electrical signal, that signal representing the aggregate of all the musical notes generated by all of the strings taken together.
Single-coil pickups are typically contained in a housing which fits neatly into any one of several cavities commonly provided on traditional electric guitars, specifically for pickups. In fact, almost all traditional electric guitars are designed to accommodate single-coil pickups in this way. In addition to fitting neatly into the traditional cavities, replacement pickups are generally sold with wiring designed to match wiring which is also commonly provided in those cavities. It is thus very convenient—and also quite common—for users to replace the factory pickups on their guitars with single-coil pickups of their own choosing, typically installing the pickups in one of the aforementioned traditional cavities. Such retrofitting allows guitar users to easily achieve desired musical qualities, which may vary from pickup to pickup.
A sub-class of single coil pickups does exist, called “Humbuckers.” Humbuckers are simply a variation of a single-coil pickup; except that instead of having the typical single coil, a Humbucker has a pair of single coils wired so as to produce signals which are opposite in phase, thereby cancelling out some “hum” inherent in single-coil pickups. For practical purposes of this discussion, Humbuckers are treated as single-coil pickups.
Many electric guitars have one or more pickups, some as many as three pickups. Generally, these multi-pickup instruments have the pickups located at specific places on the instrument to provide a variety of tonal qualities. For example, a pickup located in the cavity closest to the bridge of the instrument produces a tone in which higher frequencies are accentuated, while a pickup located in a cavity further from the bridge will produce a tone in which lower frequencies are more accentuated. A simple selector switch is generally used to select between the pickups on the instrument. Some pickups are highly prized for their tonal qualities, and there are many after-market manufacturers who produce pickups that can be easily installed by the user. It is very common for a user to replace the factory pickups on their instrument in order to achieve a desired tone.
Another, less commonly used type of pickup is called a “divided” pickup. As is true in a traditional single-coil pickup, a traditional divided pickup has a magnetic pole for each string of the instrument, with each pole being in close proximity to that respective string of the instrument. However, in contrast to the poles of single-coil pickups, each pole of the divided pickup is wrapped individually with its own coil. Such individual wrapping of each pole results in a separate electrical signal being produced for each string of the instrument. This is highly advantageous, as it affords the user the potential to modify or affect the signal from each string individually in unique ways, as opposed to processing only the aggregate signal produced by the single-coil pickup.
For example, one way of modifying the signal from each string is by altering its pitch, thereby allowing the user to create an infinite variety of harmonic and transposed musical forms. Secondly, the volume or signal level of each string can be modified independently, which allows the user to create interesting mixes such as muting certain strings or accentuating one or more strings to bring out each string's unique character. Still another capability is that of independently modifying the tone of each string, thereby allowing the user to accentuate or minimize certain frequencies of the strings. These effects could also be used to correct flaws in the sound of the strings; for example, correcting the pitch of an out-of-tune string, or raising the volume of a string that is too soft. The foregoing are just a sampling of the kinds of effects—and therefore benefits—which are made possible by using a divided pickup rather than a single coil pickup.
However, precisely because they produce multiple individual signals rather than a single aggregate signal, traditional divided pickups suffer certain significant drawbacks. For instance, if the poles and coils of the divided pickup were to be as large as those of a traditional single-coil pickup, the resulting electrical signals would be so strong as to produce cross-talk interference between the respective signals. The problem cannot be solved by increasing the distance between poles, as that would make it impossible to retain the necessary proximity of each pole to its associated string.
This cross-talk problem has commonly been solved by utilizing much smaller poles and coils, and then adding onboard pre-amplifiers to boost the resulting weaker signals, so that the signals may travel the significant distance to off-board equipment without unacceptable signal attenuation or signal interference. However, these pre-amplifiers are often bulky, and are generally aesthetically un-pleasing. Further, because the divided pickup produces a separate signal for each string, a bulky multi-pin cable is also required to effectively send the multiple signals off-board.
In addition, since traditional off-board amplifiers, speakers, foot pedals and the like are designed to operate off of a single analog signal, specialized equipment is required off-board to handle the multiple-signal output of this configuration. Traditionally, two distinct solutions have been implemented to handle this issue. One solution has been for all of the amplifiers, speakers, and other off-board equipment to be specially designed to operate off of multiple signals from a multi-pin cable. The other solution has been to provide a converter box to receive the signals from the multi-pin cable, and to convert them into a single signal compatible with traditional equipment. Both solutions have been workable; but as noted, each solution inconveniently requires additional specialized equipment.
The foregoing drawbacks of the traditional divided pickup have resulted in it being much less popular than the traditional single-coil pickup. This is unfortunate, since the divided pickup is vastly superior to the single-coil pickup in its capability of processing the sound of each string individually, as discussed above. Yet due to all of the aforementioned added components, the use of a traditional divided pickup has been inconvenient and aesthetically unappealing, as well as expensive.
In more recent years, microprocessors have been increasingly utilized to modify the electrical output signal emanating from an electric guitar, to create desired effects. These powerful microprocessors can perform complex calculations and conversions at the high speeds required for real-time pitch changes and multi-part harmony effects, for example. In particular, the power and decreasing size of microprocessors has made it feasible to take advantage of the divided pickup's potential for individually modifying the sounds from each string, through a wide variety of designs which would otherwise simply be impractical.
From the instrument perspective, all of these designs utilizing microprocessors may conveniently be divided into two distinct types: (1) onboard configurations, in which most of the processing elements are placed on the guitar itself; and (2) off-board configurations, in which the processing elements are located elsewhere than on the guitar. Space is not a concern with off-board configurations, nor are the aesthetics of large numbers of buttons and dials used to control the processing. However, it does remain desirable in the off-board environment that control be intuitive and not overwhelming in complexity. By contrast, in the onboard configurations, space, aesthetics, and straightforward and intuitive control are all constraints of paramount importance. Notably, the traditional approach in placing processing and controls onboard has essentially been merely to move all of the off-board processing and controls onto a customized instrument. Unfortunately, in practice this approach does not favor considerations of space, aesthetics, or straightforward and intuitive control, as discussed below.
An example of the onboard approach may be found in U.S. Pat. No. 5,308,916 to Murata. Murata illustrates an entirely self-contained customized instrument, in which all processing and control is located on the instrument, even including the speakers. This configuration utilizes more than thirty switches or buttons, which are located in three separate locations on the instrument. The large number of buttons and switches certainly provides the user with a great deal of control options; however, there are disadvantages to using so many buttons and switches. For one, the instrument is cluttered with all the controls, which is aesthetically un-pleasing. In addition, the very large array of buttons and switches is potentially overwhelming to the user, who may find it difficult and distracting to keep so many options straight in his mind, while still maintaining a spontaneity in his performance. Furthermore, the electronics required to implement this approach are quite bulky, due to the inclusion of so many components in a single instrument. Along those same lines, by their very nature customized guitars are typically designed with no potential for retrofitting components into the guitar. Such instruments are thus expensive to purchase, cumbersome to use, and also difficult for the average user to alter or maintain.
U.S. Pat. No. 6,111,184 to Cloud also utilizes an onboard approach, in which processing and control elements are located onboard the guitar, although Cloud does not place the speakers onboard. The Cloud design provides an onboard processor, as well as four or five buttons or switches to control the onboard processing. By utilizing a small number of controls as compared to Murata, the Cloud approach avoids some of the aforementioned problems of aesthetics and clutter associated with having a large number of controls on the instrument. However, by severely limiting the number of onboard controls, the Cloud approach also greatly restricts user control capabilities as compared to the instrument of Murata.
In addition, Cloud also provides a series of customized pickups having corresponding custom pickup cradles, which together allow the pickups to be upgraded as desired. However, these customized pickups are not interchangeable with conventional pickups. The custom cradles are designed for the custom guitar of Cloud, and would be difficult if not impossible for the average user to install, either on the custom guitar of Cloud or on a traditional guitar. This is a shortcoming of both the Cloud and Murata designs, as it is customary for users to often replace and/or upgrade their pickups with pickups of their own choosing. The pickup and the processor of Cloud are also separated from one another by some distance, which requires wiring to connect the two. At least one wire is required for each string of the instrument, making the wiring complicated and aesthetically unpleasing. This added wiring also brings with it the potential for damage to exposed wires. In addition, extending wiring between the processor and the pickup raises the potential problem of cross-talk and interference occurring in the wires. These problems become worse as the distance between the pickup and the processor increases, due to the increased potential for interference, plus the signal amplification required to send the signal over the length of the wires without undue attenuation. These problems of cross-talk and interference may require special shielding to prevent, or specialized circuitry to filter the resulting noise from the signal.
A commercially marketed custom guitar similar to Cloud and Murata designs described above was designed by the Roland Corporation, and marketed for a time by the Fender Musical Instruments Corporation. The Roland design incorporated many of the electronics, from their external foot-pedal-activated effects unit which required a special 13-pin cable to interface the effects unit with a specialized pickup installed on the guitar. Incorporating those electronics into the body of the guitar allowed Roland to process the multiple signals onboard, and to then re-mix them into a single signal to be sent off-board. In this way, Roland was able to avoid the usual requirement for a specialized multi-pin cable to carry multiple signals to off-board equipment. Because of space and design limitations, control of these electronics was limited to very simple controls, utilizing just selector knobs. The use of such simple controls severely limited user control choices, and provided limited ability for dynamic user expression. In addition, it was not easily upgradeable and was expensive. For these reasons, among others, it was not commercially successful, and was ultimately withdrawn from the market.
In addition to the shortcomings discussed above, the all-in-one approach exemplified by Murata, Cloud, and Roland suffers from other potential drawbacks. There are many widely-used off-board effects processors designed specifically to create particular effects such as reverb, delay, distortion, and amplifier/speaker simulation. Often these dedicated effects processors are quite efficient at their specialized purpose, and have unique qualities which are highly prized by musicians. Attempts by the onboard all-in-one approaches to replace these popular off-board processors with specialized proprietary processors have met with only partial success. For one thing, matching the efficient and unique performance of the off-board dedicated effects processors may require large amounts of processing power to be placed onboard the instrument, typically with a corresponding increase in control knobs and switches. Even then, it is far from certain that the desired effects will be produced as well as they would be with the dedicated off-board equipment. For these reasons, it may be disadvantageous for the musician to replace his highly prized off-board effects processors with an onboard all-in-one design.
There is thus a need for processor-driven hardware for stringed instruments which provides easily used processing and intuitive control onboard the instrument. Ideally, the processor-driven hardware would be well suited for retrofitting by the typical user into existing space(s) on the instrument, with little or no modification of the instrument itself, and with no special wiring or other installation skills required of the user. The hardware would have sufficient processing capability to provide a greatly enhanced range of effects, while still being physically unobtrusive so as to maintain the aesthetics of the instrument. The hardware would allow the user to employ a divided pickup, in order to take advantage of the capability of processing the sound from each string of the instrument, without requiring additional equipment to handle a multi-signal output generated by the divided pickup.
The custom guitars presented by Murata, Cloud and Roland also illustrate other limitations found in those designs, particularly in the musician-processor interfaces utilized in the guitars. All of those custom guitars provide buttons and switches by which the musician controls effects processing to be performed in playing the instrument. However, all of those buttons and switches are directed solely toward effects processing to be performed onboard the instrument; no attempt is made to control effects processing off-board the instrument. In Addition, while buttons and switches may accomplish their intended purpose, they are clumsy, and create clutter on the instrument and potential confusion for the musician.
There are also interface devices available in the general field of computer interface technology which are more efficient and versatile than the traditional buttons and switches. Instead of toggling on-off, or operating on a fixed scale as with traditional buttons and switches, these interfaces provide a broader range of options for input values. Such computer interface devices include the well-known keyboard, mouse, and touch pad, and variations thereon.
Keyboards are well understood and are useful for entering specific data values or for navigating menus. However, keyboards require too many keys and too much space to operate, and are thus unsuited for use on musical instruments. Mice and touch pads are particularly useful for navigating, selecting, and drawing; however, because they are peripherals dependent on a host device and designed specifically to work with graphical images, they generally require a computer environment which includes a monitor screen. This not only severely limits the types of devices with which mice and touch pads can work, but also requires the visual attention of the user in order to operate them.
Moreover, traditional touch pads such as those found on notebook computers are two-dimensional positioning devices, with no ability to sense pressure. Therefore, any “gesturing” with a touch pad is necessarily limited in scope. Such touch pads are also typically programmed only for cursor movement, plus drag, drop and click actions using buttons typically provided with touch pads. This is because the traditional touch pad is directed exclusively toward use in a windows environment (as used herein, “windows environment” refers to any software that provides multiple windows for documents or pictures on screen), and is generally intended merely as a mouse replacement. Finally, traditional touch pads do not accept multiple finger positions, as required for “pinching” or “flicking” actions.
Various attempts have been made to improve upon the traditional touch pad. U.S. Pat. No. 6,028,071 to Gillespie provides an enhanced touch pad, which has all the features of a conventional touch pad, and further includes Z-sensitivity (pressure sensitivity). The touch pad of Gillespie is thus similar to the touch screen of an I-pad. It allows the user to “flick” the screen to turn pages, and to “pinch” together items on the screen to reduce their size. However, like a traditional touch pad, the Gillespie touch pad is directed toward use with graphical images in a conventional windows environment, as found in general computing applications. Gillespie thus requires a monitor screen, which once again limits the user's options, and further requires the user's visual attention. Gillespie does mention a capability for “gestures;” however, his device seeks to act more as an enhanced replacement for a standard touch pad/mouse combination peripheral, with any built-in “gestures” being limited to the standard point, drag, drop and click actions, plus the “flick” and “pinch” actions described above. Nor is there any provision made for programming additional gestures into the device. Therefore, the Gillespie device would be of little use in a musical performance environment.
U.S. Pat. No. 7,656,394 and U.S. Patent Application Number 2006/0238520 A1 to Westerman provide a touch pad having all the features found in the Gillespie touch pad, and additionally provide a “soft” keyboard and a “soft” mouse. The touch pad of Westerman is thus entirely directed toward replacing all of the peripheral interface devices found in conventional computing—the keyboard, mouse, and touch pad. While this is clearly an enhanced interface device, it is nonetheless directed exclusively toward a windows environment, with all the aforementioned limitations associated with that environment, including the limited range of “gestures” typically found in that environment. Westerman's device would thus have little or no application as an onboard interface on a musical instrument, nor for any use other than as a peripheral device in a windows environment.
Modern tablet computers and some mobile phones have incorporated multi-touch screens which include pressure (Z-) sensitivity. These screens allow the user to employ simple “gestures” consisting of finger-tip position and pressure on a sensor surface which are interpreted as input values. When thus performed on the sensor surface of the screen, these simple gestures serve the limited purpose of navigating through the menus and displays of their respective devices. Unfortunately, those devices have yet to be successfully adapted for use onboard musical instruments. Clearly, the size, expense, and complexity of a tablet computer or other device renders them impractical for such onboard use. In addition, the devices require the user to continually refer to the display in order to operate the device, which is simply not feasible in a musical performance environment. Furthermore, the interfaces themselves are built into the tablet computer or other device, and are not capable of standing alone. The touch screen also has no intelligence of its own, and is thus not capable of being programmed to respond to user-created gestures.
U.S. Patent Application Number 2010/0020025A1 to LeMort provides a method for multiple users to collaborate using continuous multi-touch gestures. Typical uses of the LeMort method would include collaboration among users on games or business applications. While LeMort does provide continuous, multi-touch gesturing and multi-user collaboration, his method is directed primarily toward replacing traditional mouse/keyboard peripheral inputs. Its applicability to musical instruments is limited because it requires the use of a graphical display to provide visual feedback. Such a graphical display is poorly suited for use on musical instruments, in particular because a performer is typically unable to view the graphical display while performing. Finally, LeMort does not address the use of pressure as a multi-touch gesture element; thereby limiting the range of musical expression.
There is thus a need for an interface device suitable for a musician to control a microprocessor in use with a musical instrument. The interface would ideally be simple and unobtrusive, so as to avoid clutter and other aesthetic problems when used onboard the instrument. The device would be intuitive and easily used, and ideally gesture-driven, so as to avoid confusion in the rapidly paced environment common to musical performances. The device would preferably be programmable, either by the user, the vendor, or both to recognize intuitive gestures and associate them with selected commands. It would thus allow the user to use gestures which were intuitive in a musical environment, as well as for the user himself. Ideally, the musician would be able to easily perform these intuitive gestures by “feel,” without the necessity of looking at the device in order to properly input the gesture. The device would also be suitable for off-board use, and would be capable of controlling and collaborating with other users, devices or equipment in addition to musical instruments.